Knurling tool



March 20, 1951 J BQULET 2,546,058

KNURLING TOOL Filed Sept. 14, 1948 Patented Mar. 20, 1 951 UNITED STATES PATENT OFFICE KNURLING TOOL Joseph H. Boulct, Chicago, Ill.

Application September 14, 1948, Serial No. 49,171

2 Claims.

This invention relates to improvements in knurling tools, and is more particularly concerned with the provision of a knurling tool adapted for use in forming knurled surfaces on either large or small diameter stock.

In the use of knurling tools in a lathe, it has heretofore been the practice to urge the knurling rolls into contacting engagement against one side of the piece being knurled. On small diameter stock, it will be understood that the pressure exerted by the knurling rolls against one side of the stock tends to cause the stock to bend into bow-shape. It is, therefore, an object of this invention to provide a knurling tool in which the knurling rolls are adapted to be disposed to engage diametrically opposed sides of small diameter stock. When the knurling rolls are positioned on diametrically opposed sides of a piece of stock, they exert equal pressure from opposite sides of the stock and thus do not have a tendency to bend the stock out of its normal axial alignment.

' It is a further object of this invention to provide a self-centering knurling tool adapted for use in a lathe for knurling surfaces on cylindrical stock of either large or small diameter.

It is a further object of this invention to provide a knurling tool suitable for use in a shaper or planer for knurling flat surfaces.

This invention embodies other novel features, details of construction and arrangement of parts which are hereinafter set forth in the specification and claims, and illustrated in the accompanying drawing wherein:

Fig. 1 is aside elevational view illustrating a knurling tool embodying features of my invention.

- Fig. 2 is a front elevational view of same.

Fig. 3 is a top plan view of same.

Fig. 4 is a sectional view taken along the line 44 of Fig. 3, showing the position of the knurling rolls when positioned for knurling the surfaces of cylindrical stock.

Fig. 5 is a sectional view, correspondin to Fig. 4, showing the knurling rolls as positioned for knurling flat surfaces.

Fig. 6 is atransverse sectional view taken along the line 6-6 of Fig. 4.

Referring now to the .drawing .for a better understanding of this invention, the knurling tool is shown as comprising a sleeve-shape housing 6 formed. with a top'wall l, bottomwall 8 and side wallsBY-S. The housing 6 is preferably formed of one piece of metal to provide a rigid structure, but it is obvious that the housing may be formed of two or more pieces welded or otherwise secured together. A stock I l is journaled for pivotal 2 movement intermediate its ends upon a pivot pin [2 which is mounted at its ends in apertures formed in the side walls 99 of the housing 6. The forward end of the stock, indicated at I3, is preferably formed with outwardly converging top and bottom walls 14 and 15, respectively. The

forward end 13 of the stock is also formed with an aperture l 6 to receive a compression spring H.

A pair of roll supporting arms I 8 and [9 are journaled at their inner ends upon pivot pins 2] and 22, respectively, which are mounted at snugly receive knurling rolls 26 and'21 ,"'respec-' tively. The knurling rols26 and 21 are j'our-' naled upon pins 28 and 29, respectively, provided on bifurcated free ends of the supporting arms.

l8 and I9. I

The top wall land bottom wall 8 of the housing 6 are provided with threaded apertures 3|" and 32, respectively, to receive adjustment screws 33 and 34, respectively. Each adjustment screw" is preferably provided with a locking nut 36.

The portion of the stock H, indicated at 31,

is adapted to be mounted within a tool holder 38 of a lathe in knurling the outer surface of cylindrical metal or other material mounted in a chuck or between the centers of a lathe. To adapt the knurling tool for use in standard lathes, the bottom surface 38 of the stock II is disposed approximately three-quarters of an inch from the axis of the pivot pin l2, as illustrated in Fig. 4, and the axis of the pivot pin I2 is adapted to be disposed in a horizontal plane with the-axis of the cylindrical metal mounted in the lathe.

In knurling the surface of relatively large diameter metal, indicated in dotted'outline'at 39, the roll supporting arms [8 and [9 are pref erably arranged in line contact engagement with the top and bottom walls, respectively, of the housing 6. The surface of the cylindrical piece 39 is knurled in the usual manner by first moving the knurling rolls 26 and 21 into engagement ad jacent one end-of the cylindrical metal 39 and outline at 41 in Fig. 4, the knurling rolls 26 and 21 are first positioned on diametrically opposed sides of the work and then moved toward each other to engage diametrically opposed sides of the work by means of the adjustment screws 33 and 34, respectively. It will be noted that the housing 6 is free to pivot relative to the stock I i when the roll supporting arms I8 and I9 are disposed in an intermediate position between the top walls 1 and 8, respectively, and the portion is of the stock I i Thelmurling tool is thus;self-centering. In knurling relatively small diameter stock of, for example, one-eighth or one-quarter of an inch in diameter, it will be noted that the knurling tool does not exert a force tending to bend the Work as the knurling rolls 26 and 2'! are disposed on opposite sides of the work. To adapt the knurling tool for use in other types of machines; such as planers or shapers for forming a knurled surface on flat stock, indicated at 42 in Fig. of the drawing, the forward portion 13 of the stock coacts with the. adjustment; screws: 3% and 341120 lock the roll supporting arms l8 and I9. and: the: housing l5 against movement relative to. the stock H.. When, the roll supporting arms 8 and; I29; are disposed in. their inner position in abutting; engagement with opposite. surfaces of. the. portion i3 of the stock the knurling rolls and. 2''! are. in closely spaced relation and are each adapted to; engage the; flat surface of the work 42;

In. order to assuraa perfectly knurled. su-riace onv a piece-of. work,.i-t.is. essential that the several parts'ofztheg knnrling: tool. should-not: move; lateral- 1y relative to; each other; In. applicantscon- Structiion, it: is. contemplated that. the sides. of. thestock: portion; I13. and the; sides. of; the. roll. supportin -arms: t8 and. H3 should. be; in snug, frictionali en a ement: with. the; side walls. 9-9 of; the housing 6, and: further that the side; surfaces of the:- k'nurling rolls; 26: and 21; should be. finished for: snugfrictionalengagement within the bifurcatedportions 23: and 24: of they roll supporting arms. I8 and: I 9;

After reviewing the specification and drawing, itv will" be apparent. that the; knurling tool thus stock in a: lathe, or in knurling flat surfaces on stock, mounted in a. planer or shapen. It will. further be; noted that the knurling tool is selfcenteri-ng when employed in knurlingcylindrical surfaces and may readily be adjusted to accommodatezvarious types of, work.

While this invention has been shown in but i one form, it' isobvious tothose skilled in the art that it is not so. limited but is susceptible of various changes and modifications without depart-ingfrom; the spirit: and scope of the claimed: invention;

I; claim asv my. invention:

1.. A knurling-tool comprising a rigid, fiat, end-- wise; Open. sleeve-shaped housing having side walls.v and relativelynarrowtop and: bottom walls, ashank. to be engaged in the tool post of a machine havinganend, portiondisposed within said housing mediallyof said; top and, bottom Walls and snugly received between said side walls, saidend: portion; being taperedv from the. rear housing openinatdthe front opening. thereof. an.d:pivotal-- 1y. engaged adiacent'said. rear opening. a pair. of

. shank portion to yieldably resist movement of edges to define a shallow V between the. end walls,.

a shank to be engaged. in they tool post of a machine: haying. an ofiset end portion disposed within saidhousing medially of said top and bottom Wallsand; snugly received between said side walls, said end portion.- being tapered from. the rear. housing openingitov the front opening thereof andpi-yotally engaged adjacent. said rear; opening, a

pair of. rollsup orting; arms formed with arcua-te rocker ends disposed. Within said housing and.

received. between; said side walls pivotally engaged adjacent said. rear opening and adapted-- teibesuccessivelypivotally moved. into. line contact with said tapered shank; end, portion and. with the housing top; and bottom Walls, bifurcated. endportions: on the; free ends of said arms. extending outwardly of and in close proximity to the front opening of the housing and knurling rolls. journaled. therein, said. bifurcated end, pol-.- tions'. being laterally offset. and, providing, shoulders adapted to overlie and abut against the ad-- shown and described isadapted for universal use in knurling surfaces on large or small diameter JOSEPH. H. BOULET.

REFERENCES. CITED,

The following references are. of? record inthe file; of this: patent;

UNITED STATES PATENTS Number Name. Date 2,294,685 Nelson Sept. 1,1942

FOREIGN PATENTS Numberv Country Date Great Britain M... Sept. 25;. 1346- 

